/*!
 * wordcloud2.js
 * http://timdream.org/wordcloud2.js/
 *
 * Copyright 2011 - 2013 Tim Chien
 * Released under the MIT license
 */

'use strict';

// setImmediate
if (!window.setImmediate) {
    window.setImmediate = (function setupSetImmediate() {
        return window.msSetImmediate ||
            window.webkitSetImmediate ||
            window.mozSetImmediate ||
            window.oSetImmediate ||
            (function setupSetZeroTimeout() {
                if (!window.postMessage || !window.addEventListener) {
                    return null;
                }

                var callbacks = [undefined];
                var message = 'zero-timeout-message';

                // Like setTimeout, but only takes a function argument.  There's
                // no time argument (always zero) and no arguments (you have to
                // use a closure).
                var setZeroTimeout = function setZeroTimeout(callback) {
                    var id = callbacks.length;
                    callbacks.push(callback);
                    window.postMessage(message + id.toString(36), '*');

                    return id;
                };

                window.addEventListener('message', function setZeroTimeoutMessage(evt) {
                    // Skipping checking event source, retarded IE confused this window
                    // object with another in the presence of iframe
                    if (typeof evt.data !== 'string' ||
                        evt.data.substr(0, message.length) !== message/* ||
                     evt.source !== window */) {
                        return;
                    }

                    evt.stopImmediatePropagation();

                    var id = parseInt(evt.data.substr(message.length), 36);
                    if (!callbacks[id]) {
                        return;
                    }

                    callbacks[id]();
                    callbacks[id] = undefined;
                }, true);

                /* specify clearImmediate() here since we need the scope */
                window.clearImmediate = function clearZeroTimeout(id) {
                    if (!callbacks[id]) {
                        return;
                    }

                    callbacks[id] = undefined;
                };

                return setZeroTimeout;
            })() ||
            // fallback
            function setImmediateFallback(fn) {
                window.setTimeout(fn, 0);
            };
    })();
}

if (!window.clearImmediate) {
    window.clearImmediate = (function setupClearImmediate() {
        return window.msClearImmediate ||
            window.webkitClearImmediate ||
            window.mozClearImmediate ||
            window.oClearImmediate ||
            // "clearZeroTimeout" is implement on the previous block ||
            // fallback
            function clearImmediateFallback(timer) {
                window.clearTimeout(timer);
            };
    })();
}

(function (global) {

    // Check if WordCloud can run on this browser
    var isSupported = (function isSupported() {
        var canvas = document.createElement('canvas');
        if (!canvas || !canvas.getContext) {
            return false;
        }

        var ctx = canvas.getContext('2d');
        if (!ctx.getImageData) {
            return false;
        }
        if (!ctx.fillText) {
            return false;
        }

        if (!Array.prototype.some) {
            return false;
        }
        if (!Array.prototype.push) {
            return false;
        }

        return true;
    }());

    // Find out if the browser impose minium font size by
    // drawing small texts on a canvas and measure it's width.
    var minFontSize = (function getMinFontSize() {
        if (!isSupported) {
            return;
        }

        var ctx = document.createElement('canvas').getContext('2d');

        // start from 20
        var size = 20;

        // two sizes to measure
        var hanWidth, mWidth;

        while (size) {
            ctx.font = size.toString(10) + 'px sans-serif';
            if ((ctx.measureText('\uFF37').width === hanWidth) &&
                (ctx.measureText('m').width) === mWidth) {
                return (size + 1);
            }

            hanWidth = ctx.measureText('\uFF37').width;
            mWidth = ctx.measureText('m').width;

            size--;
        }

        return 0;
    })();

    // Based on http://jsfromhell.com/array/shuffle
    var shuffleArray = function shuffleArray(arr) {
        for (var j, x, i = arr.length; i;
             j = Math.floor(Math.random() * i),
                 x = arr[--i], arr[i] = arr[j],
                 arr[j] = x) {
        }
        return arr;
    };

    var WordCloud = function WordCloud(elements, options) {
        if (!isSupported) {
            return;
        }

        if (!Array.isArray(elements)) {
            elements = [elements];
        }

        elements.forEach(function (el, i) {
            if (typeof el === 'string') {
                elements[i] = document.getElementById(el);
                if (!elements[i]) {
                    throw 'The element id specified is not found.';
                }
            } else if (!el.tagName && !el.appendChild) {
                throw 'You must pass valid HTML elements, or ID of the element.';
            }
        });

        /* Default values to be overwritten by options object */
        var settings = {
            list: [],
            fontFamily: '"Trebuchet MS", "Heiti TC", "微軟正黑體", ' +
            '"Arial Unicode MS", "Droid Fallback Sans", sans-serif',
            fontWeight: 'normal',
            color: 'random-dark',
            minSize: 0, // 0 to disable
            weightFactor: 1,
            clearCanvas: true,
            backgroundColor: '#fff',  // opaque white = rgba(255, 255, 255, 1)

            gridSize: 8,
            drawOutOfBound: false,
            origin: null,

            drawMask: false,
            maskColor: 'rgba(255,0,0,0.3)',
            maskGapWidth: 0.3,

            wait: 0,
            abortThreshold: 0, // disabled
            abort: function noop() {
            },

            minRotation: -Math.PI / 2,
            maxRotation: Math.PI / 2,
            rotationSteps: 0,

            shuffle: true,
            rotateRatio: 0.1,

            shape: 'circle',
            ellipticity: 0.65,

            classes: null,

            hover: null,
            click: null
        };

        if (options) {
            for (var key in options) {
                if (key in settings) {
                    settings[key] = options[key];
                }
            }
        }

        /* Convert weightFactor into a function */
        if (typeof settings.weightFactor !== 'function') {
            var factor = settings.weightFactor;
            settings.weightFactor = function weightFactor(pt) {
                return pt * factor; //in px
            };
        }

        /* Convert shape into a function */
        if (typeof settings.shape !== 'function') {
            switch (settings.shape) {
                case 'circle':
                /* falls through */
                default:
                    // 'circle' is the default and a shortcut in the code loop.
                    settings.shape = 'circle';
                    break;

                case 'cardioid':
                    settings.shape = function shapeCardioid(theta) {
                        return 1 - Math.sin(theta);
                    };
                    break;

                /*

                 To work out an X-gon, one has to calculate "m",
                 where 1/(cos(2*PI/X)+m*sin(2*PI/X)) = 1/(cos(0)+m*sin(0))
                 http://www.wolframalpha.com/input/?i=1%2F%28cos%282*PI%2FX%29%2Bm*sin%28
                 2*PI%2FX%29%29+%3D+1%2F%28cos%280%29%2Bm*sin%280%29%29

                 Copy the solution into polar equation r = 1/(cos(t') + m*sin(t'))
                 where t' equals to mod(t, 2PI/X);

                 */

                case 'diamond':
                case 'square':
                    // http://www.wolframalpha.com/input/?i=plot+r+%3D+1%2F%28cos%28mod+
                    // %28t%2C+PI%2F2%29%29%2Bsin%28mod+%28t%2C+PI%2F2%29%29%29%2C+t+%3D
                    // +0+..+2*PI
                    settings.shape = function shapeSquare(theta) {
                        var thetaPrime = theta % (2 * Math.PI / 4);
                        return 1 / (Math.cos(thetaPrime) + Math.sin(thetaPrime));
                    };
                    break;

                case 'triangle-forward':
                    // http://www.wolframalpha.com/input/?i=plot+r+%3D+1%2F%28cos%28mod+
                    // %28t%2C+2*PI%2F3%29%29%2Bsqrt%283%29sin%28mod+%28t%2C+2*PI%2F3%29
                    // %29%29%2C+t+%3D+0+..+2*PI
                    settings.shape = function shapeTriangle(theta) {
                        var thetaPrime = theta % (2 * Math.PI / 3);
                        return 1 / (Math.cos(thetaPrime) +
                            Math.sqrt(3) * Math.sin(thetaPrime));
                    };
                    break;

                case 'triangle':
                case 'triangle-upright':
                    settings.shape = function shapeTriangle(theta) {
                        var thetaPrime = (theta + Math.PI * 3 / 2) % (2 * Math.PI / 3);
                        return 1 / (Math.cos(thetaPrime) +
                            Math.sqrt(3) * Math.sin(thetaPrime));
                    };
                    break;

                case 'pentagon':
                    settings.shape = function shapePentagon(theta) {
                        var thetaPrime = (theta + 0.955) % (2 * Math.PI / 5);
                        return 1 / (Math.cos(thetaPrime) +
                            0.726543 * Math.sin(thetaPrime));
                    };
                    break;

                case 'star':
                    settings.shape = function shapeStar(theta) {
                        var thetaPrime = (theta + 0.955) % (2 * Math.PI / 10);
                        if ((theta + 0.955) % (2 * Math.PI / 5) - (2 * Math.PI / 10) >= 0) {
                            return 1 / (Math.cos((2 * Math.PI / 10) - thetaPrime) +
                                3.07768 * Math.sin((2 * Math.PI / 10) - thetaPrime));
                        } else {
                            return 1 / (Math.cos(thetaPrime) +
                                3.07768 * Math.sin(thetaPrime));
                        }
                    };
                    break;
            }
        }

        /* Make sure gridSize is a whole number and is not smaller than 4px */
        settings.gridSize = Math.max(Math.floor(settings.gridSize), 4);

        /* shorthand */
        var g = settings.gridSize;
        var maskRectWidth = g - settings.maskGapWidth;

        /* normalize rotation settings */
        var rotationRange = Math.abs(settings.maxRotation - settings.minRotation);
        var rotationSteps = Math.abs(Math.floor(settings.rotationSteps));
        var minRotation = Math.min(settings.maxRotation, settings.minRotation);

        /* information/object available to all functions, set when start() */
        var grid, // 2d array containing filling information
            ngx, ngy, // width and height of the grid
            center, // position of the center of the cloud
            maxRadius;

        /* timestamp for measuring each putWord() action */
        var escapeTime;

        /* function for getting the color of the text */
        var getTextColor;

        function random_hsl_color(min, max) {
            return 'hsl(' +
                (Math.random() * 360).toFixed() + ',' +
                (Math.random() * 30 + 70).toFixed() + '%,' +
                (Math.random() * (max - min) + min).toFixed() + '%)';
        }

        switch (settings.color) {
            case 'random-dark':
                getTextColor = function getRandomDarkColor() {
                    return random_hsl_color(10, 50);
                };
                break;

            case 'random-light':
                getTextColor = function getRandomLightColor() {
                    return random_hsl_color(50, 90);
                };
                break;

            default:
                if (typeof settings.color === 'function') {
                    getTextColor = settings.color;
                }
                break;
        }

        /* function for getting the classes of the text */
        var getTextClasses = null;
        if (typeof settings.classes === 'function') {
            getTextClasses = settings.classes;
        }

        /* Interactive */
        var interactive = false;
        var infoGrid = [];
        var hovered;

        var getInfoGridFromMouseTouchEvent =
            function getInfoGridFromMouseTouchEvent(evt) {
                var canvas = evt.currentTarget;
                var rect = canvas.getBoundingClientRect();
                var clientX;
                var clientY;
                /** Detect if touches are available */
                if (evt.touches) {
                    clientX = evt.touches[0].clientX;
                    clientY = evt.touches[0].clientY;
                } else {
                    clientX = evt.clientX;
                    clientY = evt.clientY;
                }
                var eventX = clientX - rect.left;
                var eventY = clientY - rect.top;

                var x = Math.floor(eventX * ((canvas.width / rect.width) || 1) / g);
                var y = Math.floor(eventY * ((canvas.height / rect.height) || 1) / g);

                return infoGrid[x][y];
            };

        var wordcloudhover = function wordcloudhover(evt) {
            var info = getInfoGridFromMouseTouchEvent(evt);

            if (hovered === info) {
                return;
            }

            hovered = info;
            if (!info) {
                settings.hover(undefined, undefined, evt);

                return;
            }

            settings.hover(info.item, info.dimension, evt);

        };

        var wordcloudclick = function wordcloudclick(evt) {
            var info = getInfoGridFromMouseTouchEvent(evt);
            if (!info) {
                return;
            }

            settings.click(info.item, info.dimension, evt);
            evt.preventDefault();
        };

        /* Get points on the grid for a given radius away from the center */
        var pointsAtRadius = [];
        var getPointsAtRadius = function getPointsAtRadius(radius) {
            if (pointsAtRadius[radius]) {
                return pointsAtRadius[radius];
            }

            // Look for these number of points on each radius
            var T = radius * 8;

            // Getting all the points at this radius
            var t = T;
            var points = [];

            if (radius === 0) {
                points.push([center[0], center[1], 0]);
            }

            while (t--) {
                // distort the radius to put the cloud in shape
                var rx = 1;
                if (settings.shape !== 'circle') {
                    rx = settings.shape(t / T * 2 * Math.PI); // 0 to 1
                }

                // Push [x, y, t]; t is used solely for getTextColor()
                points.push([
                    center[0] + radius * rx * Math.cos(-t / T * 2 * Math.PI),
                    center[1] + radius * rx * Math.sin(-t / T * 2 * Math.PI) *
                    settings.ellipticity,
                    t / T * 2 * Math.PI]);
            }

            pointsAtRadius[radius] = points;
            return points;
        };

        /* Return true if we had spent too much time */
        var exceedTime = function exceedTime() {
            return ((settings.abortThreshold > 0) &&
            ((new Date()).getTime() - escapeTime > settings.abortThreshold));
        };

        /* Get the deg of rotation according to settings, and luck. */
        var getRotateDeg = function getRotateDeg() {
            if (settings.rotateRatio === 0) {
                return 0;
            }

            if (Math.random() > settings.rotateRatio) {
                return 0;
            }

            if (rotationRange === 0) {
                return minRotation;
            }

            if (rotationSteps > 0) {
                return minRotation +
                    (1 / Math.floor((Math.random() * rotationSteps) + 1)) *
                    rotationRange;
            }
            else {
                return minRotation + Math.random() * rotationRange;
            }
        };

        var getTextInfo = function getTextInfo(word, weight, rotateDeg) {
            // calculate the acutal font size
            // fontSize === 0 means weightFactor function wants the text skipped,
            // and size < minSize means we cannot draw the text.
            var debug = false;
            var fontSize = settings.weightFactor(weight);
            if (fontSize <= settings.minSize) {
                return false;
            }

            // Scale factor here is to make sure fillText is not limited by
            // the minium font size set by browser.
            // It will always be 1 or 2n.
            var mu = 1;
            if (fontSize < minFontSize) {
                mu = (function calculateScaleFactor() {
                    var mu = 2;
                    while (mu * fontSize < minFontSize) {
                        mu += 2;
                    }
                    return mu;
                })();
            }

            var fcanvas = document.createElement('canvas');
            var fctx = fcanvas.getContext('2d', {willReadFrequently: true});

            fctx.font = settings.fontWeight + ' ' +
                (fontSize * mu).toString(10) + 'px ' + settings.fontFamily;

            // Estimate the dimension of the text with measureText().
            var fw = fctx.measureText(word).width / mu;
            var fh = Math.max(fontSize * mu,
                    fctx.measureText('m').width,
                    fctx.measureText('\uFF37').width) / mu;

            // Create a boundary box that is larger than our estimates,
            // so text don't get cut of (it sill might)
            var boxWidth = fw + fh * 2;
            var boxHeight = fh * 3;
            var fgw = Math.ceil(boxWidth / g);
            var fgh = Math.ceil(boxHeight / g);
            boxWidth = fgw * g;
            boxHeight = fgh * g;

            // Calculate the proper offsets to make the text centered at
            // the preferred position.

            // This is simply half of the width.
            var fillTextOffsetX = -fw / 2;
            // Instead of moving the box to the exact middle of the preferred
            // position, for Y-offset we move 0.4 instead, so Latin alphabets look
            // vertical centered.
            var fillTextOffsetY = -fh * 0.4;

            // Calculate the actual dimension of the canvas, considering the rotation.
            var cgh = Math.ceil((boxWidth * Math.abs(Math.sin(rotateDeg)) +
                boxHeight * Math.abs(Math.cos(rotateDeg))) / g);
            var cgw = Math.ceil((boxWidth * Math.abs(Math.cos(rotateDeg)) +
                boxHeight * Math.abs(Math.sin(rotateDeg))) / g);
            var width = cgw * g;
            var height = cgh * g;

            fcanvas.setAttribute('width', width);
            fcanvas.setAttribute('height', height);

            if (debug) {
                // Attach fcanvas to the DOM
                document.body.appendChild(fcanvas);
                // Save it's state so that we could restore and draw the grid correctly.
                fctx.save();
            }

            // Scale the canvas with |mu|.
            fctx.scale(1 / mu, 1 / mu);
            fctx.translate(width * mu / 2, height * mu / 2);
            fctx.rotate(-rotateDeg);

            // Once the width/height is set, ctx info will be reset.
            // Set it again here.
            fctx.font = settings.fontWeight + ' ' +
                (fontSize * mu).toString(10) + 'px ' + settings.fontFamily;

            // Fill the text into the fcanvas.
            // XXX: We cannot because textBaseline = 'top' here because
            // Firefox and Chrome uses different default line-height for canvas.
            // Please read https://bugzil.la/737852#c6.
            // Here, we use textBaseline = 'middle' and draw the text at exactly
            // 0.5 * fontSize lower.
            fctx.fillStyle = '#000';
            fctx.textBaseline = 'middle';
            fctx.fillText(word, fillTextOffsetX * mu,
                (fillTextOffsetY + fontSize * 0.5) * mu);

            // Get the pixels of the text
            var imageData = fctx.getImageData(0, 0, width, height).data;

            if (exceedTime()) {
                return false;
            }

            if (debug) {
                // Draw the box of the original estimation
                fctx.strokeRect(fillTextOffsetX * mu,
                    fillTextOffsetY, fw * mu, fh * mu);
                fctx.restore();
            }

            // Read the pixels and save the information to the occupied array
            var occupied = [];
            var gx = cgw, gy, x, y;
            var bounds = [cgh / 2, cgw / 2, cgh / 2, cgw / 2];
            while (gx--) {
                gy = cgh;
                while (gy--) {
                    y = g;
                    singleGridLoop: {
                        while (y--) {
                            x = g;
                            while (x--) {
                                if (imageData[((gy * g + y) * width +
                                    (gx * g + x)) * 4 + 3]) {
                                    occupied.push([gx, gy]);

                                    if (gx < bounds[3]) {
                                        bounds[3] = gx;
                                    }
                                    if (gx > bounds[1]) {
                                        bounds[1] = gx;
                                    }
                                    if (gy < bounds[0]) {
                                        bounds[0] = gy;
                                    }
                                    if (gy > bounds[2]) {
                                        bounds[2] = gy;
                                    }

                                    if (debug) {
                                        fctx.fillStyle = 'rgba(255, 0, 0, 0.5)';
                                        fctx.fillRect(gx * g, gy * g, g - 0.5, g - 0.5);
                                    }
                                    break singleGridLoop;
                                }
                            }
                        }
                        if (debug) {
                            fctx.fillStyle = 'rgba(0, 0, 255, 0.5)';
                            fctx.fillRect(gx * g, gy * g, g - 0.5, g - 0.5);
                        }
                    }
                }
            }

            if (debug) {
                fctx.fillStyle = 'rgba(0, 255, 0, 0.5)';
                fctx.fillRect(bounds[3] * g,
                    bounds[0] * g,
                    (bounds[1] - bounds[3] + 1) * g,
                    (bounds[2] - bounds[0] + 1) * g);
            }

            // Return information needed to create the text on the real canvas
            return {
                mu: mu,
                occupied: occupied,
                bounds: bounds,
                gw: cgw,
                gh: cgh,
                fillTextOffsetX: fillTextOffsetX,
                fillTextOffsetY: fillTextOffsetY,
                fillTextWidth: fw,
                fillTextHeight: fh,
                fontSize: fontSize
            };
        };

        /* Determine if there is room available in the given dimension */
        var canFitText = function canFitText(gx, gy, gw, gh, occupied) {
            // Go through the occupied points,
            // return false if the space is not available.
            var i = occupied.length;
            while (i--) {
                var px = gx + occupied[i][0];
                var py = gy + occupied[i][1];

                if (px >= ngx || py >= ngy || px < 0 || py < 0) {
                    if (!settings.drawOutOfBound) {
                        return false;
                    }
                    continue;
                }

                if (!grid[px][py]) {
                    return false;
                }
            }
            return true;
        };

        /* Actually draw the text on the grid */
        var drawText = function drawText(gx, gy, info, word, weight,
                                         distance, theta, rotateDeg, attributes) {

            var fontSize = info.fontSize;
            var color;
            if (getTextColor) {
                color = getTextColor(word, weight, fontSize, distance, theta);
            } else {
                color = settings.color;
            }

            var classes;
            if (getTextClasses) {
                classes = getTextClasses(word, weight, fontSize, distance, theta);
            } else {
                classes = settings.classes;
            }

            var dimension;
            var bounds = info.bounds;
            dimension = {
                x: (gx + bounds[3]) * g,
                y: (gy + bounds[0]) * g,
                w: (bounds[1] - bounds[3] + 1) * g,
                h: (bounds[2] - bounds[0] + 1) * g
            };

            elements.forEach(function (el) {
                if (el.getContext) {
                    var ctx = el.getContext('2d');
                    var mu = info.mu;

                    // Save the current state before messing it
                    ctx.save();
                    ctx.scale(1 / mu, 1 / mu);

                    ctx.font = settings.fontWeight + ' ' +
                        (fontSize * mu).toString(10) + 'px ' + settings.fontFamily;
                    ctx.fillStyle = color;
                    ctx.shadowBlur = 5;

                    // Translate the canvas position to the origin coordinate of where
                    // the text should be put.
                    ctx.translate((gx + info.gw / 2) * g * mu,
                        (gy + info.gh / 2) * g * mu);

                    if (rotateDeg !== 0) {
                        ctx.rotate(-rotateDeg);
                    }

                    // Finally, fill the text.

                    // XXX: We cannot because textBaseline = 'top' here because
                    // Firefox and Chrome uses different default line-height for canvas.
                    // Please read https://bugzil.la/737852#c6.
                    // Here, we use textBaseline = 'middle' and draw the text at exactly
                    // 0.5 * fontSize lower.
                    ctx.textBaseline = 'middle';
                    ctx.shadowColor = color;
                    ctx.fillText(word, info.fillTextOffsetX * mu,
                        (info.fillTextOffsetY + fontSize * 0.5) * mu);

                    // The below box is always matches how <span>s are positioned
                    /* ctx.strokeRect(info.fillTextOffsetX, info.fillTextOffsetY,
                     info.fillTextWidth, info.fillTextHeight); */

                    // Restore the state.
                    ctx.restore();
                } else {
                    // drawText on DIV element
                    var span = document.createElement('span');
                    var transformRule = '';
                    transformRule = 'rotate(' + (-rotateDeg / Math.PI * 180) + 'deg) ';
                    if (info.mu !== 1) {
                        transformRule +=
                            'translateX(-' + (info.fillTextWidth / 4) + 'px) ' +
                            'scale(' + (1 / info.mu) + ')';
                    }
                    var styleRules = {
                        'position': 'absolute',
                        'display': 'block',
                        'font': settings.fontWeight + ' ' +
                        (fontSize * info.mu) + 'px ' + settings.fontFamily,
                        'left': ((gx + info.gw / 2) * g + info.fillTextOffsetX) + 'px',
                        'top': ((gy + info.gh / 2) * g + info.fillTextOffsetY) + 'px',
                        'width': info.fillTextWidth + 'px',
                        'height': info.fillTextHeight + 'px',
                        'lineHeight': fontSize + 'px',
                        'whiteSpace': 'nowrap',
                        'transform': transformRule,
                        'webkitTransform': transformRule,
                        'msTransform': transformRule,
                        'transformOrigin': '50% 40%',
                        'webkitTransformOrigin': '50% 40%',
                        'msTransformOrigin': '50% 40%'
                    };
                    if (color) {
                        styleRules.color = color;
                    }
                    span.textContent = word;
                    for (var cssProp in styleRules) {
                        span.style[cssProp] = styleRules[cssProp];
                    }
                    if (attributes) {
                        for (var attribute in attributes) {
                            span.setAttribute(attribute, attributes[attribute]);
                        }
                    }
                    if (classes) {
                        span.className += classes;
                    }
                    el.appendChild(span);
                }
            });
        };

        /* Help function to updateGrid */
        var fillGridAt = function fillGridAt(x, y, drawMask, dimension, item) {
            if (x >= ngx || y >= ngy || x < 0 || y < 0) {
                return;
            }

            grid[x][y] = false;

            if (drawMask) {
                var ctx = elements[0].getContext('2d');
                ctx.fillRect(x * g, y * g, maskRectWidth, maskRectWidth);
            }

            if (interactive) {
                infoGrid[x][y] = {item: item, dimension: dimension};
            }
        };

        /* Update the filling information of the given space with occupied points.
         Draw the mask on the canvas if necessary. */
        var updateGrid = function updateGrid(gx, gy, gw, gh, info, item) {
            var occupied = info.occupied;
            var drawMask = settings.drawMask;
            var ctx;
            if (drawMask) {
                ctx = elements[0].getContext('2d');
                ctx.save();
                ctx.fillStyle = settings.maskColor;
            }

            var dimension;
            if (interactive) {
                var bounds = info.bounds;
                dimension = {
                    x: (gx + bounds[3]) * g,
                    y: (gy + bounds[0]) * g,
                    w: (bounds[1] - bounds[3] + 1) * g,
                    h: (bounds[2] - bounds[0] + 1) * g
                };
            }

            var i = occupied.length;
            while (i--) {
                var px = gx + occupied[i][0];
                var py = gy + occupied[i][1];

                if (px >= ngx || py >= ngy || px < 0 || py < 0) {
                    continue;
                }

                fillGridAt(px, py, drawMask, dimension, item);
            }

            if (drawMask) {
                ctx.restore();
            }
        };

        /* putWord() processes each item on the list,
         calculate it's size and determine it's position, and actually
         put it on the canvas. */
        var putWord = function putWord(item) {
            var word, weight, attributes;
            if (Array.isArray(item)) {
                word = item[0];
                weight = item[1];
            } else {
                word = item.word;
                weight = item.weight;
                attributes = item.attributes;
            }
            var rotateDeg = getRotateDeg();

            // get info needed to put the text onto the canvas
            var info = getTextInfo(word, weight, rotateDeg);

            // not getting the info means we shouldn't be drawing this one.
            if (!info) {
                return false;
            }

            if (exceedTime()) {
                return false;
            }

            // If drawOutOfBound is set to false,
            // skip the loop if we have already know the bounding box of
            // word is larger than the canvas.
            if (!settings.drawOutOfBound) {
                var bounds = info.bounds;
                if ((bounds[1] - bounds[3] + 1) > ngx ||
                    (bounds[2] - bounds[0] + 1) > ngy) {
                    return false;
                }
            }

            // Determine the position to put the text by
            // start looking for the nearest points
            var r = maxRadius + 1;

            var tryToPutWordAtPoint = function (gxy) {
                var gx = Math.floor(gxy[0] - info.gw / 2);
                var gy = Math.floor(gxy[1] - info.gh / 2);
                var gw = info.gw;
                var gh = info.gh;

                // If we cannot fit the text at this position, return false
                // and go to the next position.
                if (!canFitText(gx, gy, gw, gh, info.occupied)) {
                    return false;
                }

                // Actually put the text on the canvas
                drawText(gx, gy, info, word, weight,
                    (maxRadius - r), gxy[2], rotateDeg, attributes);

                // Mark the spaces on the grid as filled
                updateGrid(gx, gy, gw, gh, info, item);

                // Return true so some() will stop and also return true.
                return true;
            };

            while (r--) {
                var points = getPointsAtRadius(maxRadius - r);

                if (settings.shuffle) {
                    points = [].concat(points);
                    shuffleArray(points);
                }

                // Try to fit the words by looking at each point.
                // array.some() will stop and return true
                // when putWordAtPoint() returns true.
                // If all the points returns false, array.some() returns false.
                var drawn = points.some(tryToPutWordAtPoint);

                if (drawn) {
                    // leave putWord() and return true
                    return true;
                }
            }
            // we tried all distances but text won't fit, return false
            return false;
        };

        /* Send DOM event to all elements. Will stop sending event and return
         if the previous one is canceled (for cancelable events). */
        var sendEvent = function sendEvent(type, cancelable, detail) {
            if (cancelable) {
                return !elements.some(function (el) {
                    var evt = document.createEvent('CustomEvent');
                    evt.initCustomEvent(type, true, cancelable, detail || {});
                    return !el.dispatchEvent(evt);
                }, this);
            } else {
                elements.forEach(function (el) {
                    var evt = document.createEvent('CustomEvent');
                    evt.initCustomEvent(type, true, cancelable, detail || {});
                    el.dispatchEvent(evt);
                }, this);
            }
        };

        /* Start drawing on a canvas */
        var start = function start() {
            // For dimensions, clearCanvas etc.,
            // we only care about the first element.
            var canvas = elements[0];

            if (canvas.getContext) {
                ngx = Math.ceil(canvas.width / g);
                ngy = Math.ceil(canvas.height / g);
            } else {
                var rect = canvas.getBoundingClientRect();
                ngx = Math.ceil(rect.width / g);
                ngy = Math.ceil(rect.height / g);
            }

            // Sending a wordcloudstart event which cause the previous loop to stop.
            // Do nothing if the event is canceled.
            if (!sendEvent('wordcloudstart', true)) {
                return;
            }

            // Determine the center of the word cloud
            center = (settings.origin) ?
                [settings.origin[0] / g, settings.origin[1] / g] :
                [ngx / 2, ngy / 2];

            // Maxium radius to look for space
            maxRadius = Math.floor(Math.sqrt(ngx * ngx + ngy * ngy));

            /* Clear the canvas only if the clearCanvas is set,
             if not, update the grid to the current canvas state */
            grid = [];

            var gx, gy, i;
            if (!canvas.getContext || settings.clearCanvas) {
                elements.forEach(function (el) {
                    if (el.getContext) {
                        var ctx = el.getContext('2d');
                        ctx.fillStyle = settings.backgroundColor;
                        ctx.clearRect(0, 0, ngx * (g + 1), ngy * (g + 1));
                        ctx.fillRect(0, 0, ngx * (g + 1), ngy * (g + 1));
                    } else {
                        el.textContent = '';
                        el.style.backgroundColor = settings.backgroundColor;
                        el.style.position = 'relative';
                    }
                });

                /* fill the grid with empty state */
                gx = ngx;
                while (gx--) {
                    grid[gx] = [];
                    gy = ngy;
                    while (gy--) {
                        grid[gx][gy] = true;
                    }
                }
            } else {
                /* Determine bgPixel by creating
                 another canvas and fill the specified background color. */
                var bctx = document.createElement('canvas').getContext('2d');

                bctx.fillStyle = settings.backgroundColor;
                bctx.fillRect(0, 0, 1, 1);
                var bgPixel = bctx.getImageData(0, 0, 1, 1).data;

                /* Read back the pixels of the canvas we got to tell which part of the
                 canvas is empty.
                 (no clearCanvas only works with a canvas, not divs) */
                var imageData =
                    canvas.getContext('2d').getImageData(0, 0, ngx * g, ngy * g).data;

                gx = ngx;
                var x, y;
                while (gx--) {
                    grid[gx] = [];
                    gy = ngy;
                    while (gy--) {
                        y = g;
                        singleGridLoop: while (y--) {
                            x = g;
                            while (x--) {
                                i = 4;
                                while (i--) {
                                    if (imageData[((gy * g + y) * ngx * g +
                                        (gx * g + x)) * 4 + i] !== bgPixel[i]) {
                                        grid[gx][gy] = false;
                                        break singleGridLoop;
                                    }
                                }
                            }
                        }
                        if (grid[gx][gy] !== false) {
                            grid[gx][gy] = true;
                        }
                    }
                }

                imageData = bctx = bgPixel = undefined;
            }

            // fill the infoGrid with empty state if we need it
            if (settings.hover || settings.click) {

                interactive = true;

                /* fill the grid with empty state */
                gx = ngx + 1;
                while (gx--) {
                    infoGrid[gx] = [];
                }

                if (settings.hover) {
                    canvas.addEventListener('mousemove', wordcloudhover);
                }

                if (settings.click) {
                    canvas.addEventListener('click', wordcloudclick);
                    canvas.addEventListener('touchstart', wordcloudclick);
                    canvas.addEventListener('touchend', function (e) {
                        e.preventDefault();
                    });
                    canvas.style.webkitTapHighlightColor = 'rgba(0, 0, 0, 0)';
                }

                canvas.addEventListener('wordcloudstart', function stopInteraction() {
                    canvas.removeEventListener('wordcloudstart', stopInteraction);

                    canvas.removeEventListener('mousemove', wordcloudhover);
                    canvas.removeEventListener('click', wordcloudclick);
                    hovered = undefined;
                });
            }

            i = 0;
            var loopingFunction, stoppingFunction;
            if (settings.wait !== 0) {
                loopingFunction = window.setTimeout;
                stoppingFunction = window.clearTimeout;
            } else {
                loopingFunction = window.setImmediate;
                stoppingFunction = window.clearImmediate;
            }

            var addEventListener = function addEventListener(type, listener) {
                elements.forEach(function (el) {
                    el.addEventListener(type, listener);
                }, this);
            };

            var removeEventListener = function removeEventListener(type, listener) {
                elements.forEach(function (el) {
                    el.removeEventListener(type, listener);
                }, this);
            };

            var anotherWordCloudStart = function anotherWordCloudStart() {
                removeEventListener('wordcloudstart', anotherWordCloudStart);
                stoppingFunction(timer);
            };

            addEventListener('wordcloudstart', anotherWordCloudStart);

            var timer = loopingFunction(function loop() {
                if (i >= settings.list.length) {
                    stoppingFunction(timer);
                    sendEvent('wordcloudstop', false);
                    removeEventListener('wordcloudstart', anotherWordCloudStart);

                    return;
                }
                escapeTime = (new Date()).getTime();
                var drawn = putWord(settings.list[i]);
                var canceled = !sendEvent('wordclouddrawn', true, {
                    item: settings.list[i], drawn: drawn
                });
                if (exceedTime() || canceled) {
                    stoppingFunction(timer);
                    settings.abort();
                    sendEvent('wordcloudabort', false);
                    sendEvent('wordcloudstop', false);
                    removeEventListener('wordcloudstart', anotherWordCloudStart);
                    return;
                }
                i++;
                timer = loopingFunction(loop, settings.wait);
            }, settings.wait);
        };

        // All set, start the drawing
        start();
    };

    WordCloud.isSupported = isSupported;
    WordCloud.minFontSize = minFontSize;

    // Expose the library as an AMD module
    if (typeof define === 'function' && define.amd) {
        global.WordCloud = WordCloud;
        define('wordcloud', [], function () {
            return WordCloud;
        });
    } else if (typeof module !== 'undefined' && module.exports) {
        module.exports = WordCloud;
    } else {
        global.WordCloud = WordCloud;
    }

})(this); //jshint ignore:line
